His argument was that the Europeans are acutely aware of how much they need us on this front, the UK has the best intelligence services in Europe, and it would be best to let the EU bring up security first.

Liam Fox, though, takes a very different view. One member of the Brexit committee tells me that the former Defence Secretary “is the one who always says they owe us on security”.

May’s judgment was that including security in the letter was a necessary reminder that the collapse of the talks would have consequences for both sides that would go far beyond just disruptions to trade.

But despite the objections of some EU leaders to this linkage, Donald Tusk’s reaction to May’s letter has been positive.

The President of the EU Council has NOT demanded that Britain settle any “divorce bill’” before talks on trade can begin. This would have been a poison pill for the talks.

The UK Government could never accept handing over billions of pounds before it even got to talk about a trade deal.

Rather, Tusk is proposing that the UK and the EU agree how the final settlement will be calculated and then move on to trade. As one UK Government source closely involved in devising the British negotiating strategy says: “This is pretty constructive.”

The biggest irritation to the government is how aggressive the outgoing French president, Francois Hollande, is being. “The Germans are difficult but sensible. The French are difficult but intransigent,” complains one Whitehall source.

But one Cabinet Minister tells me that Hollande is being this difficult precisely because he won’t be there for the actual negotiations.

One other bonus of this week for May is that she has kept her negotiating options open. There was no outcry from the hardline Eurosceptic wing of the Tory party when she didn’t rule out free movement and the role of the European Court of Justice continuing during any implementation period.

May has also accepted that the UK may well have to pay something to the EU on the way out without sparking a row. As one senior Tory backbencher tells me: “We can see things are moving in the right direction, so we’re prepared to give her time.”

The Brexit talks will not be easy. There will be times when they appeared to have collapsed. But the negotiations have got off to as good a start as the PM could have hoped.

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Scots have regarded May’s view that “now is not the time” for another referendum as fair.

So the SNP “grievance machine”, as one Downing Street aide calls it, is trying to find a way to ignite a row.

May and her ministers just need to keep their tempers. For the more the SNP look like a party that is incapable of doing anything other than angrily banging on about independence, the more they will lose support from the moderate Scottish voters they will need to win any second referendum.

BANKING ON BLIGHTY TO DELIVER

IN the next few weeks, the big investment banks will set out how they intend to deal with Brexit.

I understand that, this month, several banks will announce they are moving jobs to various EU cities.

But, crucially, each will only be moving hundreds of people, not thousands.

Just as important, they are not all going to the same place – some are heading to Dublin, others to Luxembourg and Frankfurt.

But, I’m told, Amsterdam will be the surprise winner from this process; the Dutch government has done a very effective lobbying job. The fact that the jobs are being spread around is another sign that London’s pre-eminence as Europe’s financial capital will not be challenged.

No one will be able to compete with the City’s economies of scale.

I UNDERSTAND that the Government’s informal deadline for the Northern Irish parties to reach an agreement on power-sharing is Easter.

After the holidays, Westminster will have to legislate to set the rates for local councils and that will be the beginning of a return to direct rule.

In Whitehall, there isn’t much optimism about a deal being done.

They fear Sinn Fein have decided that they would rather rail against “Tory austerity” and Brexit from the sidelines than get involved in government again.

EXPECT PRE-BUDGET FEELERS FROM PHIL

AT a drinks party for Tory MPs this week, Philip Hammond said that the lesson he had taken from having to abandon his tax hike on the self-employed was the need for more “pitch rolling” before these announcements were made.

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But this raises the question of how compatible this would be with the traditional secrecy of the Budget process. However, if Hammond wants to avoid having to make any sudden U-turns after his autumn budget, he might have to give us far more of a preview than normal of what is going to be in it.

ONE copy of Theresa May’s Article 50 letter came back from Brussels. But this isn’t a memento to be framed in the Mays’ downstairs loo. Rather, it is the diplomatic version of a receipt – confirmation that the EU had actually received the letter.

Then again, given the blanket media coverage it would have been rather hard for them to claim that it had got lost in the post.